The present invention is directed to an x-ray image intensifier which has an output window that is mounted in a metal frame that is inserted into a tube envelope of the intensifier.
An electro-optical image intensifier having an output window which is mounted in a metal frame that is inserted into a tube bulb or envelope of the intensifier is disclosed in U.S. Pat. No. 3,458,744, whose disclosure is incorporated by reference thereto. As known, in the electronic image intensifiers of the type disclosed in this patent, an x-ray picture is converted into electron images which are then subjected to an acceleration voltage and are imaged on an output screen with the size of the image adjusted as needed. In x-ray intensifiers, which are usually fashioned one-stage, when the electron image has it image adjusted for size, the image, which appears on the output screen is also the image which is observed. This, however, presumes that the output screen can be seen through the wall of the bulb or envelope of the image intensifier. For this reason, the bulb or envelope has been manufactured of a transparent material, particularly glass, at least at the location of the output screen.
In order to obtain an expediently manipulable design solution, the window, which is inserted into the bulb, has been simultaneously made the carrier of the output luminescent screen. Since, in the known design solution, the output window is held by fusing the window in a metal frame, the luminescent screen cannot be applied until after this joint or fusion process has occurred. This, however, is a disadvantage because the yield of screens which are employable later is low because of the coating with the luminophor layer so that the connection of the glass pane to the frame, which must be carried out precisely, is frequently undertaken for panes which subsequently lead to screens which are not usable.